CardDAV in iOS6

When iCloud was first launched, I set up access to iCloud accounts in Snow Leopard and iOS4 using the standard IMAP, CalDAV and CarDAV protocols which worked perfectly, as you would expect since those are exactly the protocols on which iCloud is based.

Fast forward to the present day with iOS6 on an iPhone 4. I need to get CardDAV working with an iCloud account. No problem I thought and entered in what I remembered as the correct details, but now, hours later I have simply failed to get anywhere. No matter what I enter into the server field, it spends some time verifying (maybe seconds, maybe many minutes) and then complains it cannot connect using SSL and should it try without. If I tap continue it then reports that verification failed. I'm 100% sure it needs SSL, so in fact when it fails the first step, there's no need to bother trying without SSL.

So what is it about iOS6 that is not allowing this to work. Maybe there were changes in iOS5 that also prevented this, but I've no way to confirm that. However, a test with the expected details on an iPhone 3G with iOS 4.2.1 worked perfectly, yet those same account details failed in the manner described above when it was attampted on an iPhone 5 with iOS 6.0.1.

I'm kinda stumped right now. Has anyone managed to get CardDAV to iCloud working in iOS6, or have any idea how to do it?

One more thing. I cannot get CalDAV to work either in iOS6.